Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b866d103d50a0ea…

MALICIOUS

PDF

68.1 KB Created: 2021-04-23 18:14:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-04
MD5: 4fb0c7f03697d8c5ad37d3acf2ef16f2 SHA-1: f0864f21ae3e73954d61736281d814e664e5a145 SHA-256: 8b866d103d50a0ea6f6ee1e4190b07bd4a90d8ac7145b2b6992acf1d29f161da
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable domains or link farms, suggesting a coordinated effort to redirect users. The document body, though heavily obfuscated, contains a search query that likely serves as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.friendlycc.com/sites/default/files/webform/29579557159.pdf In PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/danajon.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/90018929780.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/87706268510.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/xixarujopotagateregigo.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/kubuxodadiwozubak.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/12938533755.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/kilolegejesap.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=can+i+clean+keurig+with+apple+cider+vinegarPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/26360011081.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/85266863194.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/zuwamusijugowop.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/xafuzekimizitigemuseli.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ccb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCB1 5280 bytes
SHA-256: e032a7142c21ad1c074553540bab13609e76adf86d90194bead45de5c37be339
font_01_sfnt_off0000deb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEB5 10856 bytes
SHA-256: a33730ed9e6a4fcb68e518b1bd10a5dae29dc1acfb8fc0309eedd23822cf794a